Distribution function of the random field and polar properties of the relaxor ferroelectric films

TL;DR

This paper presents a model based on the random field theory to analyze the polar properties and phase transitions of relaxor ferroelectric thin films, considering surface effects and chemical disorder.

Contribution

It introduces a new model for relaxor ferroelectric films that incorporates the random field theory to predict properties and phase transitions.

Findings

Calculated spatial profiles and averaged properties of relaxor ferroelectric films.

Determined the dependence of the order parameter on film thickness, temperature, and distribution function.

Identified critical thickness and temperature for size-driven phase transitions.

Abstract

The model for calculation of relaxor ferroelectrics thin films properties is proposed. The basis of the model is the theory of random field. This field is originated from the chemical disorder allowing for influence of the film surfaces, which destroys the polar long-range order and transform it into mixed state of ferroelectric glass (FG) or dipole glass (DG). The spatial profiles and averaged over coordinate inside the film values of properties of relaxor ferroelectric film were calculated with the random field distribution function. As an example the dependence of the order parameter on film thickness, temperature and distribution function characteristics was obtained. The critical thickness and temperature of the size-driven phase transition from FG to DG state as a function of the film and distribution function characteristics were calculated.